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Deye Seplosv3 Modbus Register 604: Device type-Internal CT L1 Power

Technical documentation for Modbus register 604 on Deye Seplosv3. Data type: S WORD. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register device type-Internal CT L1 Power at address 604 is used to monitor device type-internal ct l1 power on the Deye Seplosv3.

  • Protocol: Modbus RTU
  • Data Type: S WORD
  • Unit: W
  • Access: Read Only

How to Read (Python pymodbus)

Use this code snippet to read this specific value via RS485:

from pymodbus.client.sync import ModbusSerialClient

client = ModbusSerialClient(method='rtu', port='/dev/ttyUSB0', baudrate=9600)
client.connect()

# Read device_type-Internal CT L1 Power (Address: 604)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=604, count=2, unit=1)

if not result.isError():
    print(f"Raw Value: {result.registers}")
else:
    print("Error reading register")

client.close()

Integration (Home Assistant)

Paste this into your configuration.yaml:

- platform: modbus_controller
  name: "device_type-Internal CT L1 Power"
  address: 604
  value_type: S_WORD
  unit_of_measurement: "W"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Deye Seplosv3]

    PLC -- "A+ (D+)" --> Device
    PLC -- "B- (D-)" --> Device
    PLC -- GND --> Device


💡 Engineer's Insight

Analysis: Line 1 internal current transformer power measurement (W). Represents real power flowing through L1.

Troubleshooting: Zero indicates no power consumption/generation on L1. Check loads, generation, and CT connections/functionality.